Windmill
For teams whose internal tools are mostly scripts and workflows.
88
sovereigntyWindmill takes the opposite approach to a drag-and-drop canvas: you write scripts in Python, TypeScript, Go or Bash and Windmill generates the UI from their inputs, alongside a workflow engine for chaining them. For an engineering team whose internal tooling is fundamentally automation with a form on top — reruns, backfills, ops jobs — that is a much better fit than a widget canvas. AGPL-3.0 core with a commercial enterprise edition. Roughly 17.5k stars, and unusually fast because the execution engine is Rust.
OPEN SOURCEAGPL-3.0 (core; enterprise edition is commercial)SELF-HOSTLOCAL-FIRST
LicenseAGPL-3.0 (core; enterprise edition is commercial)
PricingFree and open source to self-host. Paid cloud and enterprise editions.
Open sourceYes
Self-hostableYes
Local-first dataYes
What it does well
- +Script-first: the UI is generated from code you already write
- +Serious workflow engine, not an afterthought
- +Rust execution engine — genuinely fast
- +Fits engineering teams better than a drag-and-drop canvas
Where it falls short
- −Wrong shape if you want non-engineers building tools
- −AGPL-3.0 strong copyleft
- −Smaller community than Appsmith or ToolJet
- −UI generation is less flexible than hand-placed widgets
Windmill as an alternative to
Where Windmill shows up in our comparisons, and how it ranked.
Windmill head-to-head
Straight comparisons against the tools people weigh it against.